DOWNEY >> Changes to state water regulations late last year are beginning to take effect in Downey.

The more stringent regulations could significantly raise operating costs and are already complicating the water discharge permit process, city officials say.

Over the next year, Downey officials will develop six plans with the county flood control district and cities including Long Beach, Lakewood, Paramount, Signal Hill and Cerritos, to manage water runoff into the Los Angeles River, the San Gabriel River and the Los Cerritos Channel.

The city must draft two plans for each of the three waterways.

The first plan will provide an overview of pollutant sources and strategies for reducing runoff and treating pollutants. The second plan is designed to assess the environmental impact of pollutants.

According to the city, the plans will cost $160,000 to research and draft.

“The real costs will hit when we have to come up with a treatment system,” said John Oskoui, assistant city manager and public works director for Downey.

And no one knows exactly how much the treatment system will cost.

“This is the start of it,” said Dan Mueller, the city’s principal civil engineer. “Over the course of the next year we’ll have a clearer view (of future costs), but it’s going to be a moving target.”

The plans come in the wake of increased water and pollutant regulations when the state increased standards for a permit that regulates discharge from storm drains in December 2012, Mueller said.

“Before, the county used to take the lead (on the permit),” he said. “As of 2012, each agency is a permittee. Most of these (cities or groups) haven’t had to do this before.”